Персона: Леонов, Александр Сергеевич
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Институт общей профессиональной подготовки (ИОПП)
Миссией Института является:
фундаментальная базовая подготовка студентов, необходимая для получения качественного образования на уровне требований международных стандартов;
удовлетворение потребностей обучающихся в интеллектуальном, культурном, нравственном развитии и приобретении ими профессиональных знаний; формирование у студентов мотивации и умения учиться; профессиональная ориентация школьников и студентов в избранной области знаний, формирование способностей и навыков профессионального самоопределения и профессионального саморазвития.
Основными целями и задачами Института являются:
обеспечение высококачественной (фундаментальной) базовой подготовки студентов бакалавриата и специалитета; поддержка и развитие у студентов стремления к осознанному продолжению обучения в институтах (САЕ и др.) и на факультетах Университета; обеспечение преемственности образовательных программ общего среднего и высшего образования; обеспечение высокого качества довузовской подготовки учащихся Предуниверситария и школ-партнеров НИЯУ МИФИ за счет интеграции основного и дополнительного образования;
учебно-методическое руководство общеобразовательными кафедрами Института, осуществляющими подготовку бакалавров и специалистов по социо-гуманитарным, общепрофессиональным и естественнонаучным дисциплинам, обеспечение единства требований к базовой подготовке студентов в рамках крупных научно-образовательных направлений (областей знаний).
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Леонов
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Александр Сергеевич
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31 results
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- ПубликацияТолько метаданныеON THE PROPERTIES OF A FAST ALGORITHM FOR SOLVING A THREE-DIMENSIONAL INVERSE PROBLEM OF SCALAR ACOUSTICS(2024) Bakushinsky, A. B.; Leonov, A. S.; Леонов, Александр Сергеевич
- ПубликацияТолько метаданныеSolution of the Inverse Elastography Problem in Three Dimensions for a Parametric Class with A Posteriori Error Estimation(2019) Sharov, A. N.; Yagola, A. G.; Leonov, A. S.; Леонов, Александр Сергеевич© 2019, Pleiades Publishing, Ltd.The paper presents the solution of a special three-dimensional inverse elastography problem: given a quasistatic model of a linear-elastic isotropic body subject to surface forces, to find the Young’s modulus distribution in the biological tissues under study using the known values of vertical displacements of these tissues. This study is aimed at detecting local inclusions in the tissue interpreted as tumors with values of the Young’s modulus that are significantly different from the known background. In addition, it is assumed that Young’s modulus is a constant function inside the unknown inclusions of a parametrically given geometry. This inverse problem leads to the solution of a nonlinear operator equation, which is reduced by a variational method to the extremum problem of finding the number of inclusions, parameters defining their shape, and the Young’s modulus for each inclusion. The problem is solved algorithmically by using a modification of the method of extending compacts by V. K. Ivanov and I. N. Dombrovskaya. To illustrate how the algorithm works, we give examples of solving model inverse problems with inclusions in the form of balls. A posteriori error estimation of the obtained distribution of Young’s modulus is carried out for the found solution to one of the model problems.
- ПубликацияТолько метаданныеInverse problem for coefficients of equations describing propagation of COVID-19 epidemic(2021) Leonov, A. S.; Nagornov, O. V.; Tyuflin, S. A.; Леонов, Александр Сергеевич; Нагорнов, Олег Викторович; Тюфлин, Сергей Александрович© 2021 Institute of Physics Publishing. All rights reserved.The inverse problems for coefficients of ordinary differential equations describing propagation of coronavirus infection are studied. The well-known models of SEI and SEIR, and their generalization are used. Important role plays the coefficients of these equations that can be estimated by in-direct observations and depends on many factors. This approach allowed us to solve the problem with several waves of epidemic and to predict further propagation.
- ПубликацияТолько метаданныеMultifrequency Inverse Problem of Scalar Acoustics: Remarks on Nonuniqueness and Solution Algorithm(2023) Bakushinsky, A. B.; Leonov, A. S.; Леонов, Александр СергеевичA three-dimensional multifrequency inverse problem of acoustic sounding of a stationary inhomogeneous medium is considered. This nonlinear inverse problem is reduced to solving an auxiliary three-dimensional linear Fredholm integral equation of the first kind. In the analysis of the uniqueness of the solution to the inverse problem, the connection between the integral equation and determining the source in the Helmholtz equation is indicated. The last problem is ambiguously solvable in the general case. Examples of such ambiguity are given. Questions about detailed data (frequencies, sources) ensuring or not the uniqueness of solutions are considered. A speed-efficient algorithm for solving the inverse problem based on Fourier transforms is proposed. This algorithm makes it possible to calculate uniquely an approximate solution by a stable method under data perturbations. The results of numerical experiments on solving a three-dimensional model inverse problem on fairly detailed grids are presented.
- ПубликацияТолько метаданныеAssessment of Tracks of Resonance Frequencies of the Vocal Tract(2023) Leonov, A. S.; Sorokin, V. N.; Леонов, Александр Сергеевич
- ПубликацияТолько метаданныеMethods for Solving Ill-Posed Extremum Problems with Optimal and Extra-Optimal Properties(2019) Leonov, A. S.; Леонов, Александр СергеевичThe notion of the quality of approximate solutions of ill-posed extremum problems is introduced and a posteriori estimates of quality are studied for various solution methods. Several examples of quality functionals which can be used to solve practical extremum problems are given. The new notions of the optimal, optimal-in-order, and extra-optimal qualities of a method for solving extremum problems are defined. A theory of stable methods for solving extremum problems (regularizing algorithms) of optimal-in-order and extra-optimal quality is developed; in particular, this theory studies the consistency property of a quality estimator. Examples of regularizing algorithms of extra-optimal quality for solving extremum problems are given.
- ПубликацияТолько метаданныеModeling the Solution of the Acoustic Inverse Problem of Scattering for a Three-Dimensional Nonstationary Medium(2024) Bakushinsky, A. B.; Leonov, A. S.; Леонов, Александр Сергеевич
- ПубликацияОткрытый доступModeling of Mechanisms of Wave Formation for COVID-19 Epidemic(2023) Leonov, A.; Nagornov, O.; Tyuflin, S.; Леонов, Александр Сергеевич; Нагорнов, Олег Викторович; Тюфлин, Сергей Александрович
- ПубликацияТолько метаданныеOn Phase Correction in Tomographic Research(2020) Wang, Y.; Lukyanenko, D. V.; Shinkarev, V. D.; Yagola, A. G.; Leonov, A. S.; Леонов, Александр Сергеевич© 2020, Pleiades Publishing, Ltd.Abstract: Under consideration is the problem of improving the contrast of the image obtained byprocessing tomographic projections with phase distortion. The study is based on the well-knownintensity transfer equation. Unlike other works, this equation is solved in a bounded region ofvariation of the tomographic parameters. In a domain, a boundary value problem is posed for theintensity transfer equation which is then specialized for a three-dimensional parallel tomographicscheme. The case of two-dimensional tomography is also considered, together with thecorresponding boundary value problem for the intensity transfer equation. We propose numericalmethods for solving the boundary value problems of phase correction. The results are given of thenumerical experiments on correction of tomographic projections and reconstruction of thestructure of the objects under study (in particular, a slice of a geological sample) by usingpiecewise uniform regularization.
- ПубликацияТолько метаданныеSolving Some Inverse Problems of Gravimetry and Magnetometry Using an Algorithm That Improves Matrix Conditioning(2024) Leonov, A. S.; Lukyanenko, D. V.; Yagola, A. G.; Леонов, Александр Сергеевич